Dairy farmers collect milk from herd animals using extraction machinery in the form of milking machines. A dairy farmer will periodically process his or her herd with such machinery to extract milk to be used in food or dairy products.
In the case of dairy cows a set of four teatcups are employed to extract milk simultaneously from the four quarters of the cow's udder. These four teatcups are generally connected together at a single point to a common supply tube or line for milk extracted, with the resulting collection of four cups commonly being referred to as a milking unit. Vacuum or low pressure is applied to these four teatcups simultaneously to deliver the milk extracted into a single collection line, commonly known as the ‘long milk tube’.
The four distinct udder quarters and associated teats express milk with various qualities due to microbiological infections which can occur independently in each udder quarter. Furthermore, medications delivered to the animal to combat such infections can form a contaminant in the milk expressed by each quarter.
As part of quality control regime, existing sensing and analytical equipment can be used to test the milk obtained for such contaminants or the presence of microbiological infections. However, an infection or other contaminants present in one udder quarter only will produce milk which is subsequently diluted by milk obtained from the other, potentially healthy quarters of the udder. This, can for example, make it difficult to detect the start of an infection in one quarter only of the cow's udder.
It is also known to test the foremilk or the composite volume of milk extracted from individual quarters of a dairy animal to obtain an accurate and sensitive sample used to indicate the presence of such contaminants or infections. However, using traditional milking machinery and equipment, there is no facility provided for the extraction, sampling or testing of foremilk instead of the main volume of milk to be extracted.
One potential mechanism which could be employed to sample or test the milk produced per quarter, would be to place the particular type of sensor or transducer required within the teatcup used for each quarter of the udder. A single sensor can be provided for each teatcup to in turn sample the milk extracted from a single quarter.
However this approach is not necessarily practical as the sensor required would be placed in a relatively hazardous environment. The sensor used would be exposed to moisture and dirt on a frequent basis and would also be in danger of mechanical damage through being kicked or trodden on by the rear hooves of a cow.
Furthermore, the provision of multiple sensors would be a relatively expensive mechanism due to the costs of the multiple components used. The provision of multiple sensors or transducers will also require multiple calibration procedures or runs to be implemented frequently to ensure accurate results may be obtained from each sensor. Data or control signal transmission lines to such sensors would also need to be run through this hazardous environment and again, would be subject to maintenance and damage problems.
An improved sensor apparatus for extraction machinery (and preferably milking machinery) which addressed any or all of the above problems would be of advantage. An apparatus which minimised the number of independent transducers required and which could independently test the milk extracted from each test and udder section of a dairy animal would be of advantage. Furthermore, a sensor apparatus which maintained or positioned sensor transducers in a relatively secure, clean, dry and/or easily accessible environment would be of advantage.
All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.
It is acknowledged that the term ‘comprise’ may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term ‘comprise’ shall have an inclusive meaning—i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term ‘comprised’ or ‘comprising’ is used in relation to one or more steps in a method or process.
It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.